In future investigations, the following known confounding factors should be considered: bleeding source (location, type, number, size), endoscopic interventions and medical treatment used during the management of the index bleeding, additional medical therapy (antiplatelets, non-steroid anti-inflammatory drugs), DOAC effect modifying conditions (renal or hepatic impairment), and medications (CYP3A4/P-gp modifying drugs) as well as Helicobacter pylori infection in peptic ulcer disease. The gene discussed is CYP3A4; the disease is peptic ulcer disease.